Industrial machines such as gas turbines have numerous parts having holes therein that require inspection using eddy currents or ultrasound. For example, a bolt hole in a gas turbine part may require such inspection to identify cracks, etc. One challenge in using eddy current and ultrasonic inspection methods is that they require very precise manipulation of the inspection probe. Performing inspections on inner diameter surfaces of larger diameters (e.g., over 2.5 centimeters) makes probe manipulation very difficult. Another challenge is that a probe that employs a single sensor necessitates very long inspection times due to proper inspection coverage requirements. In addition, a single sensor probe requires complex manipulation to ensure adequate inspection coverage.